worker/migrationmaster: Improve test data naming
worker/migrationmaster: Improve test data naming

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kat-co/juju,AdamIsrael/juju,marcmolla/juju,mjs/juju,ericsnowcurrently/juju,howbazaar/juju,bac/juju,frankban/juju,AdamIsrael/juju,bz2/juju,AdamIsrael/juju,waigani/juju,mikemccracken/juju,dimitern/juju,dimitern/juju,bac/juju,reedobrien/juju,gabriel-samfira/juju,perrito666/juju,bz2/juju,perrito666/juju,macgreagoir/juju,mjs/juju,kat-co/juju,ericsnowcurrently/juju,ericsnowcurrently/juju,frankban/juju,bz2/juju,ericsnowcurrently/juju,kat-co/juju,alesstimec/juju,anastasiamac/juju,waigani/juju,mikemccracken/juju,waigani/juju,marcmolla/juju,bz2/juju,frankban/juju,reedobrien/juju,dimitern/juju,axw/juju,axw/juju,macgreagoir/juju,perrito666/juju,gabriel-samfira/juju,axw/juju,kat-co/juju,frankban/juju,mjs/juju,mjs/juju,marcmolla/juju,marcmolla/juju,alesstimec/juju,macgreagoir/juju,mjs/juju,anastasiamac/juju,mikemccracken/juju,reedobrien/juju,reedobrien/juju,mikemccracken/juju,alesstimec/juju,anastasiamac/juju,mikemccracken/juju,AdamIsrael/juju,bac/juju,marcmolla/juju,howbazaar/juju,reedobrien/juju,bac/juju,mjs/juju,alesstimec/juju,dimitern/juju,howbazaar/juju,alesstimec/juju,waigani/juju,bac/juju,axw/juju,axw/juju,macgreagoir/juju,kat-co/juju,howbazaar/juju,macgreagoir/juju,ericsnowcurrently/juju,gabriel-samfira/juju,perrito666/juju,bz2/juju,anastasiamac/juju,mjs/juju,perrito666/juju,gabriel-samfira/juju,gabriel-samfira/juju,frankban/juju,howbazaar/juju,anastasiamac/juju,dimitern/juju